Premium
Sm 3 Cl[SiO 4 ] 2 : Ein chlorarmes Chloridorthosilicat des Samariums
Author(s) -
Sieke Corinna,
Schleid Thomas
Publication year - 1999
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/(sici)1521-3749(199903)625:3<377::aid-zaac377>3.0.co;2-l
Subject(s) - orthosilicate , orthorhombic crystal system , crystallography , cationic polymerization , molar ratio , chemistry , samarium , ampoule , crystal structure , tetraethyl orthosilicate , inorganic chemistry , catalysis , polymer chemistry , organic chemistry
Sm 3 Cl[SiO 4 ] 2 : A Chlorine‐poor Chloride Orthosilicate of Samarium Pale yellow, plate‐like single crystals of Sm 3 Cl[SiO 4 ] 2 (orthorhombic, Pnma; a = 701.74(8), b = 1800.8(2), c = 626.63(7) pm; Z = 4) are obtained upon the reaction of SmCl 3 , Sm 2 O 3 and SiO 2 (”Kieselgel””) in 1 : 4 : 6 molar ratios, most advantageously in the presence of substantial amounts of NaCl as fluxing agent, after seven days at 850 °C in evacuated silica ampoules. The B‐type crystal structure (isotypic with e. g. Yb 3 Cl[SiO 4 ] 2 ) contains discrete orthosilicate tetrahedra [SiO 4 ] 4– which form anionic double layers ({(Sm1) 2 [SiO 4 ] 2 } 2– ) with (Sm1) 3+ . These are alternatingly sheethed along [010] with cationic monolayers ({(Sm2)Cl} 2+ ) consisting of (Sm2) 3+ and Cl – . Both crystallographically independent Sm 3+ cations exhibit coordination numbers of eight (Sm1: 1 Cl + 7 O; Sm2: 2 Cl + 6 O) with respect to the involved electronegative particles.